Re: [PATCH 1/2] LSM: Do not apply mmap_min_addr check to PROT_NONEmappings

From: Eric Paris
Date: Mon Oct 24 2011 - 11:07:55 EST


On Sun, 2011-10-23 at 11:52 -0700, Roland McGrath wrote:

> > But that's no reason for the kernel to *allow* the mapping.
>
> I don't have a problem with that.

I feel like, and it's just a very vague feeling, that the PROT bits
didn't matter to the kernel. It would still happily execute stuff on
page 0 even without PROT_EXEC at some point in the past. I'm probably
totally off base, and I could test it, but I sort of feel like I
remember something like that....

If that's the case, NULL pointer kernel bugs won't be caught if they
happen while these are mapped by your program...

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/